Technical Field
Embodiments of the present disclosure relate to an optical deflection apparatus, an image projector, an optical writing unit, and an object recognition device.
Background Art
Optical deflection apparatuses that two-dimensionally scan a laser beam emitted from a light source are known in the art.
Such an optical deflection apparatus includes a sub-scanning oscillation unit that oscillates around a sub-scanning oscillation axis, and a mirror unit that oscillates around a circumferential oscillation axis. The sub-scanning oscillation unit is supported by a supporting unit through an arm so as to be rotatable in the sub-scanning direction, and the mirror unit is supported by the sub-scanning oscillation unit through a plurality of beams in a main-scanning oscillation axis so as to be rotatable around the main-scanning oscillation axis. A piezoelectric circuit including a piezoelectric element is mounted on the surface of each beam. Due to the extension and contraction of the piezoelectric element, the beams elastically deform to rotate the mirror unit around the main-scanning oscillation axis and make the sub-scanning oscillation unit oscillate around the sub-scanning axis. Accordingly, the laser beam incident on the mirror unit performs two-dimensional scanning (deflection).